1. Field of the Invention
The present invention relates to an apparatus for detecting information indicative of the rotation of an engine which detects a rotational reference position of an engine and a rotational angle with respect to the rotational reference position.
2. Description of the Prior Art
In a conventional rotational information detecting apparatus of this type, a multiplicity of magnetic poles are formed on one track along the circumference of a rotating member to provide information as to an angle or angular information, and magnetic poles independent of the angular information are formed on a different track to provide reference information on the rotation of the rotating member. The angular information and rotational reference information are detected by the angle sensor and the rotational reference sensor respectively.
In view of the fact that the angular information and the rotational reference information are formed independently of each other on different tracks, it is difficult to synchronize the detection signal for the angular information with that of the reference rotational information, resulting in a displacement of detection between the angular and rotational reference information. Further, it is necessary to shield the sensors from each other in order to prevent the detection signal for one sensor from affecting that for the other.